1. Field of the Invention
This invention concerns vehicle framework, and more particularly, to an improved rear frame structure for an automobile which incorporates a pair of vertically oriented strut towers and a pair of laterally extending cross beam assemblies for supporting rear suspension components wherein a high degree of accuracy in spacing and alignment of the strut tower results to very accurately position associated suspension assemblies including springs and shock absorbers. This reduces vibration and noise transmission from the suspension components to the vehicle structure during operation of the vehicle due to the significant increase in strengthening.
2. Description of Related Art
Prior to the present invention various reinforced rear frame structures and strut mountings have been designed to operatively mount the rear suspension components with the object of providing a comfortable ride and increased storage space within the vehicle body in the form of an enlarged luggage/cargo space.
For example, U.S. Pat. No. 4,408,794, for "Support Column for Automotive Vehicle Wheel Suspension Assembly", issued Oct. 11, 1983, discloses a rear frame structure with support columns or suspension strut towers that are connected at an upper end by a thin-walled upper rear shelf panel and at a lower end by a substantially flat floor panel. With this construction, the suspension strut towers are designed to support rear wheel suspension components but are not readily adjustable relative to any supports for establishing a high degree of accuracy in spacing or parallelism.
In U.S. Pat. No. 5,350,214, for "Rear Body Structure for Automotive Vehicle", issued Sep. 27, 1994, opposing suspension strut towers are connected at their lower ends to special gusset constructions which are in turn connected to a floor cross member and are connected at their upper ends by gussets which are in turn connected to a panel-like rear shelve tray, thereby requiring additional means to stiffen the corners of a pass-through structure which reduces the opening size and the utility of the pass-through feature.
In U.S. Pat. No. 4,950,025, issued Aug. 21, 1990 for "Automobile Rear Body Structure" a rear deck, fenders, inner panels and rear wheel houses are joined to form a compartment for receiving external forces such as from road shock imparted through the rear wheel suspension struts.
In U.S. Pat. No. 5,660,415, issued Aug. 26, 1997 for "Torque Box Assembly for a Vehicle", a torque box for mounting a rear suspension trailing link is shown attached to a vehicle frame side rail and a body side rail for receiving external forces such as from road shock imparted through the rear wheel suspension.
In U.S. patent application Ser. No. 08/678,285, filed Jul. 11, 1996, entitled "Bracket With Floating Tap Plate for Connecting Vehicle Suspension to Body" a fastener for attaching a portion of a vehicle suspension to a vehicle body is disclosed.
While the framing arrangements disclosed in these prior patents provide various constructions and improvements to the vehicle body structures, they incorporate additional parts, assembly operations, and expense to achieve any degree of accuracy to provide a stable suspension strut platform for mounting suspension components, all of which contribute to improved passenger comfort and ride quality for occupants of a vehicle. More particularly, the prior constructions do not provide modern standards of body stiffness without added reenforcing components and the like such as reenforcements at joints. Resultantly, the suspension springs and shock absorbers cannot operate with high efficiency to better isolate the vehicle body from road induced vibrations. In contrast, this invention's frame structure produces a high degree of frame rigidity and a substantial reduction in the transmittal of vibrational energy into the vehicle body from the suspension, all without adding parts and increasing weight.